[llvm] [CodeGen] Ensure clearRegisterKills clears inside bundles. (PR #149177)
Ricardo Jesus via llvm-commits
llvm-commits at lists.llvm.org
Tue Aug 5 09:32:52 PDT 2025
https://github.com/rj-jesus updated https://github.com/llvm/llvm-project/pull/149177
>From dfa67db235787d763db1afa13023928e759a76dd Mon Sep 17 00:00:00 2001
From: Ricardo Jesus <rjj at nvidia.com>
Date: Wed, 16 Jul 2025 10:20:09 -0700
Subject: [PATCH 1/3] [CodeGen] Ensure clearRegisterKills works inside bundles.
---
llvm/lib/CodeGen/MachineInstr.cpp | 8 ++++----
.../test/CodeGen/AArch64/sve-vls-ldst-opt.mir | 20 +++++++++++++++++++
2 files changed, 24 insertions(+), 4 deletions(-)
diff --git a/llvm/lib/CodeGen/MachineInstr.cpp b/llvm/lib/CodeGen/MachineInstr.cpp
index da3665b3b6a0b..a966add78a97e 100644
--- a/llvm/lib/CodeGen/MachineInstr.cpp
+++ b/llvm/lib/CodeGen/MachineInstr.cpp
@@ -2177,12 +2177,12 @@ void MachineInstr::clearRegisterKills(Register Reg,
const TargetRegisterInfo *RegInfo) {
if (!Reg.isPhysical())
RegInfo = nullptr;
- for (MachineOperand &MO : operands()) {
- if (!MO.isReg() || !MO.isUse() || !MO.isKill())
+ for (MIBundleOperands O(*this); O.isValid(); ++O) {
+ if (!O->isReg() || !O->isUse() || !O->isKill())
continue;
- Register OpReg = MO.getReg();
+ Register OpReg = O->getReg();
if ((RegInfo && RegInfo->regsOverlap(Reg, OpReg)) || Reg == OpReg)
- MO.setIsKill(false);
+ O->setIsKill(false);
}
}
diff --git a/llvm/test/CodeGen/AArch64/sve-vls-ldst-opt.mir b/llvm/test/CodeGen/AArch64/sve-vls-ldst-opt.mir
index 49453bc178914..28c5220642ec5 100644
--- a/llvm/test/CodeGen/AArch64/sve-vls-ldst-opt.mir
+++ b/llvm/test/CodeGen/AArch64/sve-vls-ldst-opt.mir
@@ -72,3 +72,23 @@ body: |
# CHECK: STURQi killed renamable $q1, renamable $x1, 16 :: (store (s128))
# CHECK: STURQi killed renamable $q2, renamable $x1, 48 :: (store (s128))
# CHECK: STR_ZXI killed renamable $z3, renamable $x1, 4 :: (store (<vscale x 1 x s128>))
+---
+name: clear-kill-in-bundle
+tracksRegLiveness: true
+body: |
+ bb.0:
+ liveins: $x0, $z0
+
+ STR_ZXI $z0, $x0, 0 :: (store (<vscale x 1 x s128>))
+ BUNDLE implicit-def $z1, implicit-def $q1, implicit killed $z0 {
+ $z1 = ADD_ZZZ_D $z0, killed $z0
+ }
+ STR_ZXI renamable $z1, $x0, 1 :: (store (<vscale x 1 x s128>))
+
+ RET_ReallyLR
+...
+# CHECK-LABEL: name: clear-kill-in-bundle
+# CHECK: BUNDLE implicit-def $z1, implicit-def $q1, implicit $z0 {
+# CHECK: $z1 = ADD_ZZZ_D $z0, $z0
+# CHECK: }
+# CHECK: STPQi $q0, $q1, $x0, 0 :: (store (<vscale x 1 x s128>))
>From a3632c764ae5213aa609e557e51d867d49054d61 Mon Sep 17 00:00:00 2001
From: Ricardo Jesus <rjj at nvidia.com>
Date: Fri, 18 Jul 2025 08:37:36 -0700
Subject: [PATCH 2/3] Make clearRegisterKills bundle aware.
---
llvm/include/llvm/CodeGen/MachineInstr.h | 9 +++++----
llvm/lib/CodeGen/MachineInstr.cpp | 25 ++++++++++++++++--------
2 files changed, 22 insertions(+), 12 deletions(-)
diff --git a/llvm/include/llvm/CodeGen/MachineInstr.h b/llvm/include/llvm/CodeGen/MachineInstr.h
index 94d04b82666be..68eba13fef454 100644
--- a/llvm/include/llvm/CodeGen/MachineInstr.h
+++ b/llvm/include/llvm/CodeGen/MachineInstr.h
@@ -880,9 +880,9 @@ class MachineInstr
/// queries but they are bundle aware.
enum QueryType {
- IgnoreBundle, // Ignore bundles
- AnyInBundle, // Return true if any instruction in bundle has property
- AllInBundle // Return true if all instructions in bundle have property
+ IgnoreBundle, // Ignore bundles
+ AnyInBundle, // Check/update property for any instruction in bundle
+ AllInBundle // Check/update property for all instructions in bundle
};
/// Return true if the instruction (or in the case of a bundle,
@@ -1700,7 +1700,8 @@ class MachineInstr
/// Clear all kill flags affecting Reg. If RegInfo is provided, this includes
/// all aliasing registers.
LLVM_ABI void clearRegisterKills(Register Reg,
- const TargetRegisterInfo *RegInfo);
+ const TargetRegisterInfo *RegInfo,
+ QueryType Type = AllInBundle);
/// We have determined MI defined a register without a use.
/// Look for the operand that defines it and mark it as IsDead. If
diff --git a/llvm/lib/CodeGen/MachineInstr.cpp b/llvm/lib/CodeGen/MachineInstr.cpp
index a966add78a97e..1672e65a70111 100644
--- a/llvm/lib/CodeGen/MachineInstr.cpp
+++ b/llvm/lib/CodeGen/MachineInstr.cpp
@@ -2174,16 +2174,25 @@ bool MachineInstr::addRegisterKilled(Register IncomingReg,
}
void MachineInstr::clearRegisterKills(Register Reg,
- const TargetRegisterInfo *RegInfo) {
+ const TargetRegisterInfo *RegInfo,
+ QueryType Type) {
if (!Reg.isPhysical())
RegInfo = nullptr;
- for (MIBundleOperands O(*this); O.isValid(); ++O) {
- if (!O->isReg() || !O->isUse() || !O->isKill())
- continue;
- Register OpReg = O->getReg();
- if ((RegInfo && RegInfo->regsOverlap(Reg, OpReg)) || Reg == OpReg)
- O->setIsKill(false);
- }
+
+ auto clearKills = [&](auto Operands) {
+ for (MachineOperand &MO : Operands) {
+ if (!MO.isReg() || !MO.isUse() || !MO.isKill())
+ continue;
+ Register OpReg = MO.getReg();
+ if ((RegInfo && RegInfo->regsOverlap(Reg, OpReg)) || Reg == OpReg)
+ MO.setIsKill(false);
+ }
+ };
+
+ if (Type != AllInBundle || !isBundled() || isBundledWithPred())
+ clearKills(operands());
+ else
+ clearKills(mi_bundle_ops(*this));
}
bool MachineInstr::addRegisterDead(Register Reg,
>From f00a8651ad94ee369f25d2bc72f105b4954845a9 Mon Sep 17 00:00:00 2001
From: Ricardo Jesus <rjj at nvidia.com>
Date: Tue, 5 Aug 2025 09:28:39 -0700
Subject: [PATCH 3/3] Use Type == IgnoreBundle for non-bundle path.
---
llvm/lib/CodeGen/MachineInstr.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/llvm/lib/CodeGen/MachineInstr.cpp b/llvm/lib/CodeGen/MachineInstr.cpp
index 1672e65a70111..c9a85bcb0531e 100644
--- a/llvm/lib/CodeGen/MachineInstr.cpp
+++ b/llvm/lib/CodeGen/MachineInstr.cpp
@@ -2189,7 +2189,7 @@ void MachineInstr::clearRegisterKills(Register Reg,
}
};
- if (Type != AllInBundle || !isBundled() || isBundledWithPred())
+ if (Type == IgnoreBundle || !isBundled() || isBundledWithPred())
clearKills(operands());
else
clearKills(mi_bundle_ops(*this));
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